Several processes require the concentration of particles. Particles may be suspended or carried in a first volume of liquid and for additional processing, it may be useful to concentrate the particles into a second volume that is less than the first volume. For example, within the biological sciences there exists a need for concentrating cells. One example where this is necessary is during an apheresis procedure where cellular components of blood, e.g., leukocytes, erythrocytes, thrombocytes, are separated/concentrated from other liquid components such as plasma. Another example is the post processing of cells that may be grown in a liquid medium for therapeutic or research purposes. The cells may be separated/concentrated with respect to the liquid medium in which they are grown. The separation or concentration of the cells must occur without having a significant effect on their viability for later use.
Embodiments of the present invention have been made in light of these and other considerations. However, the relatively specific problems discussed above do not limit the applicability of the embodiments of the present invention.